Currently, a wide range of portable consumer electronics that are not dedicated to audio playback provide increasingly important audio capabilities. These portable consumer electronics may include, for example, smart phones, laptops, notebooks, tablet computers, and personal digital media players. These portable consumer electronics are often constrained in both x-y area and z-height or thickness such that the speaker driver included therein must be designed to meet the sizing constraints while providing adequate sound quality. Such as speaker assembly might be referred to as a “micro” speaker assembly. The micro speaker assembly may have a micro speaker acoustic chamber housing a micro speaker or micro speaker driver that has at least one dimension that is smaller than 20 millimeters (mm), and an acoustic output port. The acoustic chamber may be a plastic housing referred to as a speaker box, and may create a “back volume” for the micro speaker.
Typically, a micro speaker driver in a portable consumer electronic such as a smart phone includes a coil and a magnet unit and is completely enclosed in the acoustic chamber. One disadvantage of this configuration is that the coil generates heat when audio is being played and the plastic housing traps the generated heat in the speaker driver. If components of the driver or housing exceed a given temperature, they may become damaged, inoperative or melt. In addition, if the magnet unit exceeds a given temperature, the magnet unit may become demagnetized and this will result in terminal damage to the speaker driver.